The invention relates to a device for expandingly remodelling a hollow object consisting of a body with a mouth opening and a bottom, for instance a metal can, a blown plastic, for instance PET, bottle or the like, which device comprises:
a mould comprising two mould parts, which mould parts are relatively movable between a closed position, in which they bound a mould cavity having a form which corresponds with the desired final form of an object, and an open position in which an object for remodelling can be placed and a remodelled object can be removed; PA1 sealing means for sealing the mouth opening against the wall of the closed mould cavity; PA1 compression means for increasing the pressure in the object placed in the closed mould cavity such that the object is thereby expanded against the wall of the mould cavity; PA1 decompression means for subsequently decreasing this pressure such that the mould parts can be moved to their open position in which a remodelled object can be removed.
Such a device is known from PCT International Publication Number WO-A-95/08410.
The known device makes use of supply of an explosive mixture into the object. By igniting thereof an internal pressure increase takes place which causes the object to expand and to assume a form which corresponds with that of the wall of the mould cavity. A pressure equalization with the ambient then takes place which is accompanied by a considerable noise production. The energy generated by the explosion is wholly lost in this manner.
It is an object of the invention to embody a device of the described type such that the noise production is considerably reduced and at least a part of the energy developed in exerting internal pressure is retained for the purpose of building up pressure in a following cycle for remodelling a subsequent object.